JP2007078700A - Semiconductor magnetoresistive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-sensitivity magnetic sensor with less temperature dependence, which can operate in a large temperature range, using a simple drive circuit. <P>SOLUTION: A semiconductor magnetoresistive device has four element sections, comprising semiconductor thin film to produce magnetoresistive effect, wiring section and bonding electrodes; these four element sections producing magnetoresistive effect are connected in a bridge structure; two of those four element sections positioned on remote sides of the bridge structure are allocated in a state of vertically receiving the magnetic field of the same strength at the same time; and the element sections are connected with the bonding electrodes on the wiring section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor thin film magnetic sensor and a method of manufacturing the same.

  Magnetic sensors such as magnetoresistive elements and hall elements using compound semiconductor thin films with high electron mobility such as InSb have a function to detect a static magnetic field, and the rotational angle or speed of the gear can be adjusted regardless of whether the rotational speed is high or low. It has a function that can be detected. For this reason, it is often used as a magnetic sensor for a small DC motor.

However, InSb has a problem that it cannot meet the strict requirements in the field of application of magnetic sensors, which is expanding in recent years. For example, a magnetic sensor using InSb has a high sensitivity and extremely good characteristics near room temperature, but the resistance value of the magnetosensitive part greatly depends on the temperature. Electrical noise can be easily picked up by increasing the voltage, and at a high temperature exceeding 120 ° C., the driving current increases due to a large decrease in the element resistance value, which makes driving difficult. That is, InSb has a large temperature dependency with a maximum temperature change rate of -2% / ° C. The temperature change rate β _R of the resistance is obtained by the following formula.

Resistance temperature change rate β _R (% / ° C.) = (1 / R) dR / dT × 100

In the present invention, a small temperature change in resistance value generally means that the temperature change rate β _R (% / ° C.) is small.

  In recent years, magnetic sensors have been widely used as non-contact sensors, and their application range has been expanded. In these recently expanded fields of application of magnetic sensors, there is an increasing demand to use magnetic sensors as non-contact sensors even at lower and higher temperatures than conventional applications. Generally, the temperature range in which the magnetic sensor is driven tends to expand. In applications such as small DC motors used in conventional VTRs and personal computers, the magnetic sensor can be used in a temperature range near room temperature, for example, in the range of about -20 to 80 ° C. (actual driving temperature range of 100 ° C.). Although it was sufficient, it is actually used in a temperature range of -50 ° C to 150 ° C (actual driving temperature range of 200 ° C) in an automotive non-contact magnetic sensor or an industrial non-contact magnetic sensor that is expected to expand in the future. As required.

  Since InSb has a large temperature dependence, for example, when the temperature change rate is negative, the resistance value is high at low temperatures and low resistance at high temperatures. When the temperature changes from −50 ° C. to + 150 ° C., the resistance value at −50 ° C. 28 to 30 times the resistance value at 150 ° C. (54 times when the temperature change rate of the resistance is −2%). For this reason, the fluctuation of the resistance value becomes the fluctuation of the input resistance of the magnetic sensor as it is, the destruction due to overcurrent occurs at high temperature, and a large driving input current is required. In a small integrated driving circuit, the stability of the element Driving becomes difficult. That is, a complicated and expensive drive circuit is required. Further, at low temperatures, the element resistance becomes very large, and it is strongly influenced by stray electromagnetic noise, or causes malfunction due to noise. As a result, the magnetic sensor can be used only in a very limited case, and the merit as the non-contact sensor has not been fully utilized.

  Such a magnetic sensor and the power supply that drives the magnetic sensor and the control circuit of the magnetic sensor that amplifies the output of the magnetic field detection are small, low cost, and high performance. The temperature dependence of the value is a major obstacle. For example, the ratio between the resistance value of −50 ° C. and the resistance value of 150 ° C. at the maximum is required to be 15 times or less in absolute value.

  The present invention has been made to solve the above-described problems in the conventional magnetic sensor, and an object of the present invention is to provide a high sensitivity, low temperature dependence, and a simple driving circuit in a wide temperature range. It is to provide a magnetic sensor that can operate. Furthermore, the subject of this invention is providing the magnetic sensor which can be driven with high reliability in the range of -50 degreeC-150 degreeC, and can be driven with a small and low-cost control circuit. More specifically, a change in the input resistance value of the magnetic sensor between a low temperature (for example, a required lower limit temperature of −50 ° C.) and a high temperature (for example, a required upper limit temperature of 150 ° C.). It is an object of the present invention to provide a highly sensitive and highly reliable magnetic sensor with a small amount of noise.

  Furthermore, when driving a magnetic sensor over a wide temperature range from high to low temperature, a large thermal stress is applied through the package of the magnetic sensor, and a passivation technology that protects the magnetic sensitive part from new thermal stress is also required. It is also an object of the present invention to answer such a need.

  The inventors of the present invention have studied the composition, thinning, doping, and the like of a compound semiconductor thin film having a high electron mobility that enables the production of a highly sensitive magnetic sensor, and the matching with a control circuit. In particular, as a result of examining and focusing on the temperature dependence of the element resistance value or the change in the element resistance value between low and high temperatures, a thin film with high electron mobility that can suppress the temperature change of the input resistance of the magnetic sensor and The production method could be found. As a result, they found a magnetic sensor with little resistance temperature change.

  Furthermore, when driving a magnetic sensor in a wide temperature range from high temperature to low temperature, a large thermal stress is applied through the package of the magnetic sensor, but the insulation has the same properties as the III-V group compound semiconductor constituting the magnetosensitive part. Passivation technology that protects the magnetosensitive part from thermal stress directly received by the magnetosensitive part directly from the inorganic passivation layer (protective layer) by forming an intermediate layer of a conductive III-V compound semiconductor on the magnetosensitive part I found it. As a result, it was possible to find a magnetic sensor structure that can be driven in a wide temperature range and with high reliability.

  Furthermore, it has been found that the magnetic sensor can be driven in a wide temperature range with a small control circuit if the temperature change of the input resistance of the magnetic sensor is within a certain range.

  Furthermore, the magnetic sensor device is a combination of a high-sensitivity magnetic sensor that uses a compound semiconductor thin film that can achieve high mobility satisfying such conditions as a magnetic sensitive part and a small control circuit for the magnetic sensor. Thus, a digital output magnetic sensor device capable of outputting an output proportional to the detection signal of the magnetic field and a plurality of signals corresponding to the detection / non-detection of the magnetic field and a manufacturing method thereof have also been found.

The semiconductor magnetoresistive device of the present invention has four element portions, wiring portions, and bonding electrodes made of a semiconductor thin film on a smooth substrate surface and generating four magnetoresistance effects. Are connected in a bridge structure, and of the four element parts, two element parts in a positional relationship of the edges of the bridge structure are simultaneously arranged to receive a magnetic field of the same intensity vertically, The element part and the bonding electrode are connected by the wiring part. Here, the wiring portions may not intersect. Moreover, it may be formed so that the resistance values of the wiring portions from the connection point connecting the four element portions to the bonding electrode are equal. The semiconductor thin film is a _single- layer In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) thin film layer directly formed on a substrate, The layer may include at least one donor atom selected from the group consisting of Si, Te, S, Sn, Ge, and Se. Alternatively, the semiconductor thin film is a _single- layer In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) thin film layer formed directly on a substrate, The thin film layer has an electron concentration of 2.1 × 10 ¹⁶ / cm ³ or more, and the relationship between the electron mobility μ (cm ² / V · s) and the electron concentration n (1 / cm ³ ) of the thin film layer But,
Log ₁₀ (n) + 4.5 × 10 ⁻⁵ × μ ≧ 18.0
It is desirable to satisfy.

There is a large correlation between the electron concentration of InGaAsSb thin film and the temperature dependence of resistance. In particular, when the electron concentration of the thin film is 2.1 × 10 ¹⁶ / cm ³ or more, the temperature change of the resistance is reduced, the temperature drift of the offset voltage of the magnetic sensor is reduced, and the noise is also reduced.

In the magnetic sensor of the present invention, an In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y) having an electron concentration of 2.1 × 10 ¹⁶ / cm ³ or more on a substrate having a smooth surface. The thin film of ≦ 1) is epitaxially grown and formed as an operating layer of the magnetosensitive portion. Hereinafter, in this specification, In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) is abbreviated as InGaAsSb as necessary for the sake of simplification. The contents include all compositions determined by the above x and y.

In the present invention, the electron concentration of the thin film needs to be 2.1 × 10 ¹⁶ / cm ³ or more, preferably 5 × 10 ¹⁶ / cm ³ or more, and is 6 × 10 ¹⁶ / cm ³ or more. More preferably, it is 6 * 10 < ¹⁶ > -5 * 10 < ¹⁸ > / cm < ³ >.

One method for increasing the electron concentration of the InGaAsSb thin film is to include a small amount of donor atoms such as Si, Te, S, Sn, Ge, Se in the InGaAsSb layer. By doping the donor atom in this way, the decrease in the resistance value of the InGaAsSb layer at a high temperature can be reduced, so that a large current can be prevented from flowing through the magnetic sensor at a high temperature. As another method for increasing the electron concentration of the In _x Ga _1-x As _y Sb _1-y thin film (0 <x ≦ 1, 0 ≦ y ≦ 1), by appropriately setting the composition of the thin film, That is, the electron concentration can be increased by appropriately selecting the values of x and y within the range of 0 <x ≦ 1 and 0 ≦ y ≦ 1.

  If the electron concentration can be set to a specific level, the temperature change of the resistance can be suppressed, and the load of the control circuit of the magnetic sensor including the circuit for amplifying the output of the magnetic sensor and the power supply circuit for driving the magnetic sensor can be reduced. Can be reduced. In addition, the circuit itself is not complicated, driving power and current at high temperature are reduced, and a control circuit capable of driving the element in a wide temperature range can be manufactured. As a result, the element driving circuit can be simplified and downsized. For this reason, the magnetic sensor of the present invention and a control circuit, which is a small Si integrated circuit, are housed in one package, and a highly sensitive and reliable small thin film magnetic sensor can be realized.

  The doped magnetic sensor can avoid a sudden drop in the resistance value of the magnetic sensor in a high temperature range, and thus operates stably in a high temperature range of 100 ° C. or higher, and even in a low temperature range of −20 ° C. or lower. A rapid increase in the resistance value (input resistance value) can be reduced, and the device operates stably even in a low temperature range of −20 ° C. or lower. Complicating the circuit for amplifying the sensor output is avoided, and it is possible to manufacture a magnetic sensor that operates stably over a wide temperature range at a low cost. The effect of doping is an effect common to the embodiments of the present invention, but is not limited to the embodiments listed in the present invention.

  The donor atom to be doped is not particularly limited as long as it is an element that can be a donor, but Si, Te, S, Sn, Se, Ge, and the like can be given as typical donor atoms. By adjusting the amount of donor atom to be doped, the electron concentration in the InGaAsSb thin film can be set to an appropriate value.

  As an example, the effect of doping on InSb will be described with reference to FIG.

In the case of an InSb thin film having an electron concentration of 1.7 × 10 ¹⁶ / cm ³ without doping impurities (I), when the electron concentration is 6.6 × 10 ¹⁶ / cm ³ by doping Si (II), When Si was doped and the electron concentration became 16.0 × 10 ¹⁶ / cm ³ , the change in resistance value was examined in the temperature range of −50 ° C. to 150 ° C. for (III). The results are shown in Table 1 and FIG. As is apparent from FIG. 1, the temperature dependence of the resistance is reduced by doping the InSb thin film with Si. That is, in the case of (I) where the electron concentration not doped is 1.7 × 10 ¹⁶ / cm ³ , the resistance value at −50 ° C. is 31 times the resistance value at 150 ° C., and it is difficult to use in a low temperature region. It was. However, when (II) is doped with an electron concentration of 5 × 10 ¹⁶ / cm ³ or more, a substantially flat line is shown, and when the electron concentration is (III) above 8 × 10 ¹⁶ / cm ³ , It shows a flatter line than in the case of (II) where the electron concentration is lower than (III). The graph of the resistance value with respect to the temperature change is most preferably horizontal, but when the resistance value at −50 ° C. is higher than the resistance value at 150 ° C., it is preferably within 15 times, and within 8 times. More preferred. Further, when the resistance value at 150 ° C. is higher than the resistance value at −50 ° C., the resistance value at 150 ° C. is preferably within 3 times, and more preferably within 2 times.

＊（ ）内の数字は−５０℃における抵抗値が１５０℃における抵抗値の
何倍になるかを示している。

* Numbers in parentheses indicate how many times the resistance value at -50 ° C is higher than the resistance value at 150 ° C.

The thickness of the In _x Ga _1-x As _y Sb _1-y thin film (0 <x ≦ 1, 0 ≦ y ≦ 1), which is the operation layer of the magnetic sensor of the present invention, is generally preferably 6 μm or less, and 2 μm. The following is more preferable, and in some cases 1 micron or less is more preferable. In addition, a magnetic sensor with high magnetic field sensitivity and low resistance temperature dependence is preferable because it can produce a sensor with good characteristics at 0.7 to 1.2 microns. In the case of a magnetic sensor that requires a high-resistance input resistance value, the thin film as the magnetic sensitive portion is preferably thinner, and may be manufactured with a thickness of 0.5 microns or less, or 0.1 microns or less. Thus, when the thickness of the magnetosensitive thin film is 1 micron or less, a buffer layer (barrier layer) that is a semiconductor insulating layer or a high resistance layer having a lattice constant approximate to the lattice constant of InGaAsSb is used, for example, as the lattice constant. It is preferable to form a buffer layer having a difference of 2% or less between the thin film and the substrate or on the surface of the thin film.

  In the present invention, when the buffer layer is formed so as to be in contact with the InGaAsSb thin film that is the operation layer of the magnetic sensor, in order to set the electron concentration of the operation layer to an appropriate value near the interface with the operation layer, Instead of doping the working layer, the buffer layer may be doped with a donor atom. Note that the buffer layer serves as a layer for confining electrons to the operation layer (InGaAsSb thin film). When the operating layer is an extremely thin film of 500 mm or less, a buffer layer may be formed above and below the operating layer. In such a case, the buffer layer has a role of confining electrons in the operating layer. The layer becomes a quantum well. Further, the operation layer of the quantum well may be doped with a donor atom.

  As the substrate of the present invention, an insulating or semi-insulating compound semiconductor such as GaAs or InP is usually used. In the present invention, the surface of the substrate may further have an insulating or semi-insulating surface or a surface layer having a high sheet resistance value. In this case, in addition to the insulating substrate material described above, a Si single crystal substrate, a ferrite substrate, a ceramic substrate, or the like can be preferably used. The crystal plane orientation may be anything such as (100), (111), and is not limited. Moreover, the surface inclined about 0-10 degrees may be sufficient with respect to these surface orientations. In addition, an alumina substrate or a sapphire substrate having a smooth surface, a single crystal ferrite substrate having a thin insulating layer on the surface, or the like can be used. Even if the crystalline denser ferrite substrate produced by applying isostatic pressing at high temperature, so-called HIP, is polycrystalline, it is preferable if a heat-resistant insulating layer is formed on the surface. Can be used in the present invention.

Up to now, InSb or In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) thin film or the like is used as the thin film of the magnetic sensing portion of the magnetic sensor, that is, the operation of the magnetic sensor When used as a layer, a protective film such as Si ₃ N ₄ or SiO ₂ formed thereon, a so-called passivation thin film and an InSb thin film, In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) Since the difference in the lattice constant of the crystal lattice of a thin film such as a thin film is large, the electron mobility may be reduced by 20 to 30% due to the interaction at the crystal boundary, and the sensitivity of the magnetic sensor is reduced. Was invited. However, since InSb has a high electron mobility and is a good magnetic sensor material, the present situation is that a magnetic sensor is manufactured using InSb even if there is a large mismatch of crystal lattices. Considering the reliability in particular, it is preferable to form a passivation thin film, so that the device characteristics are deteriorated. When the thickness of the magnetic sensitive part thin film is reduced, the power consumption of the magnetic sensor is reduced and the sensitivity is increased, the characteristic deterioration is also increased. For this reason, it is significant to produce a high-sensitivity magnetic sensor by fully exploiting the thin film characteristics of InSb or In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1). It was an issue.

In order to solve this problem, as a preferred embodiment in the present invention, at least one intermediate layer is formed so as to be in direct contact with the InGaAsSb thin film constituting the magnetic sensing portion of the magnetic sensor. The intermediate layer is an insulating layer or a high resistance layer made of a III-V group compound semiconductor material. The intermediate layer is generally different from the buffer layer (barrier layer), but may also serve as the buffer layer depending on necessity. Furthermore, the intermediate layer preferably has an insulating or semi-insulating Al _x In that has a lattice constant approximate to that of an InGaAsSb thin film, a large band gap, and a lower electron mobility than the thin film. It is a thin film high resistance layer of _1-x Sb (0 <x ≦ 1) or Ga _y In _1-y Sb (0 <y ≦ 1). The difference in lattice constant from InGaAsSb is preferably within 8%, and more preferably within 5%. Furthermore, a III-V group compound semiconductor layer having a large band gap such as GaAs formed at a low temperature, but not directly in contact with the InGaAsSb thin film constituting the magnetic sensing part of the magnetic sensor is formed. Well done. That is, a plurality of intermediate layers are also formed. In addition to such an intermediate layer, a passivation thin film layer such as SiO ₂ or Si ₃ N ₄ that is not a semiconductor, that is, a protective layer is often formed on the intermediate layer.

  Such an intermediate layer is generally formed on the upper side of the thin film. Alternatively, it may be formed on both surfaces of the thin film. When a buffer layer (in the present invention, a layer formed on the upper side of the thin film is sometimes referred to as a “barrier layer” for convenience) is formed on the upper surface of the thin film, the intermediate layer is formed on the barrier layer. Formed in contact.

  If such an intermediate layer of compound semiconductor is formed on the upper side of the InGaAsSb thin film or barrier layer, the protective film formed as a passivation does not directly contact the operating layer of the magnetosensitive portion, so that a protective film exists. Nevertheless, the characteristics of the InGaAsSb thin film, particularly the electron mobility, do not change. Such an effect is particularly remarkable when the thickness of the thin film is 0.2 microns or less. In the case of an intermediate layer whose difference from the lattice constant of the thin film is within 2%, such an intermediate layer can also serve as a barrier layer.

  In the present invention, the thickness of the intermediate layer is not particularly limited, but is usually 2 microns or less, preferably 1 micron or less, and more preferably 0.5 microns or less. In particular, the layer formed on the surface is 0.5 microns or less, preferably 0.2 microns or less, more preferably 0.1 microns or less. When an intermediate layer is formed in contact with the thin film, the intermediate layer may be doped with a donor atom such as Si, Se, Te, S, Sn, or Ge. However, the donor atom may be uniformly doped in the entire intermediate layer, but may be doped in a part of the intermediate layer, for example, biased toward the surface in contact with the thin film. In this case, at least a part of the donor atom needs to be cationized.

  The intermediate layer has a property that the electron mobility is extremely small as compared with the InGaAsSb thin film and the conductivity is small, so that it does not contribute to electrical conduction although it is a semiconductor. Therefore, it behaves as an insulating layer. Furthermore, since it is disposed between the InGaAsSb thin film and the passivation layer, the interaction caused when the InGaAsSb thin film directly contacts the passivation layer is prevented, and the deterioration of the characteristics of InGaAsSb is prevented. Therefore, in a magnetic sensor having an insulating inorganic layer (protective layer) as a passivation layer, an InGaAsSb thin film, a semiconductor intermediate layer having a large band gap and a lower electron mobility than an InGaAsSb operating layer, and an insulating layer as a passivation layer It is preferable to have an inorganic layer (protective layer) in this order. An insulating or high resistance GaAs layer formed at a low temperature is a preferred example that is often used as an intermediate layer.

  The magnetic sensor of the present invention is a high-sensitivity magnetic sensor that uses an InGaAsSb thin film as a magnetically sensitive portion, and specifically includes a Hall element, a magnetoresistive element, an element that combines the Hall effect and the magnetoresistive effect, or It is a thin film magnetic sensor that detects magnetism by these effects.

  A magnetic sensor packaged together with a control circuit having at least a circuit for amplifying the output of the magnetic sensor and a power supply circuit for driving the magnetic sensor is also a magnetic sensor of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to FIGS. 2A to 7C. However, unless otherwise specified, the same reference numerals in the drawings have the same functions. The circuit shown in the present invention is an equivalent circuit.

FIG. 2A is a plan view of a Hall element which is an embodiment of a magnetic sensor having the In _x Ga _1-x As _y Sb _1-y thin film (0 <x ≦ 1, 0 ≦ y ≦ 1) of the present invention as an operation layer. FIG. 2B is a sectional view taken along line IIB-IIB ′ in FIG. 2A. 2A and 2B, the InGaAsSb thin film 2 is formed on an insulating substrate 1. The electron concentration of the thin film 2 is 2.1 × 10 ¹⁶ / cm ³ , and the input resistance value of the magnetic sensor at −50 ° C. is within 15 times the input resistance value at 150 ° C. In the figure, 3 is an inorganic protective layer formed on the entire surface excluding the external connection electrode 5, 4 is a wiring portion made of a metal thin film, and the electrode 5 for connection with the outside and a cross pattern in the center. The operation layers of the magnetic sensing unit 6 indicated by are connected. The magnetic sensing unit 6 detects a magnetic field as a magnetic sensor.

  In the present invention, the InGaAsSb thin film 2 is doped with impurities (donor atoms) such as Si, Te, Sn, S, Se, and Ge.

  FIG. 3 shows a magnetic sensor in which the Hall element 20 of the present invention is packaged in a resin package. In FIG. 3, 7 is bonding for connecting the electrode 5 (51, 52, 53) of the Hall element and the lead 8, and 9 is resin of the package.

  FIG. 4 shows a plan view of a three-terminal magnetoresistive element of the present invention having three external connection electrodes. An InGaAsSb thin film 2 and an electrode 5 for external connection are formed on a substrate 1. Reference numeral 6 denotes a magnetic sensing part for detecting a magnetic field as a magnetic sensor. Reference numeral 10 denotes a high-conductivity portion formed in ohmic contact with the InGaAsSb of the magnetosensitive portion in order to increase the magnetoresistance effect of the InGaAsSb thin film, and is a short bar electrode.

  When a constant voltage is applied to the electrode 5 (51 and 53) and a magnetic field is applied, the potential of the output terminal of the electrode 5 (52) varies depending on the magnitude of the magnetic field, and the magnetic field can be detected.

  5A and 5B show a magnetoresistive element of another embodiment of the magnetic sensor of the present invention. 5A is a plan view of the magnetoresistive element, and FIG. 5B is a sectional view taken along the line VB-VB ′ of FIG. 5A. In the magnetoresistive element of this aspect, four magnetoresistive element portions are arranged in a bridge on one plane and connected. 5A and 5B, an InGaAsSb thin film 2 is formed on a substrate 1, and a metal short bar electrode 10 is formed on the thin film 2. The electrode 5 for connection to the outside and the magnetoresistive element part are connected by the wiring part 4, and the inorganic thin film often formed as a passivation layer as needed is a protective film 3 for protecting the magnetoresistive element. . As shown in FIGS. 5A and 5B, the four magnetoresistive element portions 61, 62, 63, and 64, which are the magnetic sensitive portions 6, are arranged in a bridge shape, so that they are in a positional relationship between the sides. The two magnetoresistive element portions (61 and 63, 62 and 64) can simultaneously receive a magnetic field of the same strength in the vertical direction. In the present invention, “connected in a bridge” means not only when the magnetoresistive elements are connected in a bridge, but also when the magnetoresistive elements are connected outside the substrate. The case where it is arranged in a bridge shape is also included. The magnetoresistive element portion 21 and the short bar electrode 10 constitute a magnetoresistive element portion 6 (61, 62, 63, 64). The magnetoresistive effect depends on the shape of the magnetoresistive element portion 6 (61, 62, 63, 64) between the short bar electrodes, and the length (L) and the width (W) of the magnetoresistive element portion in the current traveling direction. The smaller the ratio (L / W), the greater the resistance change rate.

  The wiring part 4 to which the magnetoresistive element part 6 is connected may be composed of only a single layer without intersecting, but the length of the wiring part may be shortened depending on the position where the electrodes 5 (51, 52, 53, 54) are arranged. In order to achieve this, a three-dimensional multilayer structure in which the wiring portions intersect at least at one place may be employed.

  In addition, it is preferable that the resistance values of the wiring portions from the connection point of the adjacent magnetoresistive element portions to the external connection electrodes are equal to each other in order to reduce the offset voltage. Note that the resistance value of the wiring portion is 1% or less, more preferably 0.5% or less, compared to the resistance value of the magnetoresistive element portion at room temperature.

  The thinner the InGaAsSb thin film of the magnetoresistive element portion, the better. This is because the thinner the film thickness, the larger the element resistance, the smaller the chip size with the same element resistance, and the shorter the manufacturing time, which is advantageous in terms of cost. The film thickness is desirably 7 microns or less, further desirably 5 microns or less, further desirably 3 microns or less, further desirably 2 microns or less, and further desirably 1 micron or less. The highest sheet resistance is obtained and the chip size is minimized. And most desirable.

  Further, the InSb thin film of the magnetoresistive element portion preferably has a variation in sheet resistance value within 5% as a standard deviation.

In the present invention, a semiconductor insulating layer which approximates the lattice constant of the substrate between the InGaAsSb thin film and the substrate (or high resistance _{layer) Al X Ga y In z As} s Sb t Bi u (x + y + z = 1, s + t + u = 1, 0 ≦ x, y, z, s, t, u ≦ 1) are preferably formed. The difference between the lattice constant of the semiconductor insulating layer and the lattice constant of InGaAsSb is preferably within 7%. The band gap of the layer needs to be larger than that of the working layer. With such a structure, a thin thin film of InSb or InGaAsSb having a high resistance can be easily obtained, and a magnetic sensor with low power consumption can be obtained, which is practically useful. In addition, there is little deterioration in the characteristics of InGaAsSb in the device manufacturing process.

The semiconductor insulating layers are often formed above and below the InGaAsSb thin film. In particular, when the thickness of the InGaAsSb thin film is 1 micron or less, semiconductor insulating layers are often formed above and below. As an example of such a semiconductor insulating layer, Al _x Ga _1-x As _y Sb _1-y (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, where x and y are not 0 simultaneously) A ternary or quaternary compound semiconductor insulating layer made of is a particularly preferable example.

FIG. 6A shows a cross-sectional structure in a state in which the semiconductor thin film 2 which is the operation layer of the magnetic sensor of the present invention is formed directly on the insulating substrate 1. FIG. 6B shows a cross section in a state in which the semiconductor insulating layer 11 is formed between the insulating substrate 1 and the semiconductor thin film 2 to reduce the difference in lattice constant. FIG. 6C is a cross-sectional view in the case where the semiconductor insulating layer 11 for reducing the difference in lattice constant is formed on the surface of the semiconductor thin film 2, and the effect of reducing the deterioration of the characteristics of the thin film insulating layer during the passivation of Si ₃ N ₄ or the like. In other words, a semiconductor insulating layer is formed. FIG. 7A shows a cross-sectional structure in a state where the intermediate layer 13 is formed on the semiconductor thin film 2, and FIG. 7B shows that the semiconductor insulating layer 11 is formed between the semiconductor thin film 2 and the intermediate layer 13. The cross-sectional structure of a state is shown.

  The semiconductor insulating layer 11 or the intermediate layer 13 may be doped with a donor atom 12 such as Si in order to supply electrons into the InGaAsSb thin film. However, doping may be performed on a part of the semiconductor insulating layer (or intermediate layer). In this case, electrons of at least a part of the donor atom are supplied to the InGaAsSb layer having low energy. Then, the donor atom of the semiconductor insulating layer (or intermediate layer) is positively ionized. FIG. 7C shows the case where the semiconductor insulating layer is partially doped in this way. In FIG. 7C, a donor atom 12 is doped in a region in contact with the semiconductor thin film 2 in the semiconductor insulating layer 11.

  The thickness of such a semiconductor insulating layer is not particularly limited, but is usually 2 microns or less, preferably 1 micron or less, more preferably 0.5 microns or less. When a semiconductor insulating layer is formed on the surface, it is necessary to form an ohmic electrode on the InSb surface, and the thickness of the layer is preferably 0.5 microns or less, more preferably 0.2 microns or less, particularly 0 .1 micron or less is preferable.

  The example which uses the thing of the said structure for the magnetic sensing part of the magnetic sensor of this invention is shown. For example, in the case of the structure of FIG. 6A, the semiconductor thin film 2 is formed directly on the insulating substrate. When the magnetic sensor is a magnetoresistive element, a metal short bar electrode is formed directly on the semiconductor thin film 2. Is done. In the case of the structure shown in FIG. 6B, a semiconductor insulating layer is formed between the insulating substrate and the semiconductor thin film, and a short bar is formed on the semiconductor thin film. In the case of the structure of FIG. 6C, a semiconductor insulating layer is formed on the surface, and a part of the layer is removed to form a short bar electrode. In the present invention, a part of the semiconductor thin film may be doped to form a short bar effect so as to have high conductivity.

  FIG. 8 shows a magnetoresistive element 18 according to the present invention packaged together with a control circuit portion 14 of a silicon integrated circuit chip having an analog amplification portion 15, a Schmitt trigger 16 and an output portion 17 (shown as an output transistor). Indicates the state. This is also included in the magnetic sensor of the present invention. Here, the control circuit unit 14 means a control circuit having at least a differential amplification circuit and a power supply circuit for driving the magnetic sensor, and is preferably small, and particularly manufactured as a silicon integrated circuit chip. It is preferable. It is often packaged together with the magnetoresistive element 18 of the present invention, which is also a magnetic sensor of the present invention.

[Reference Example 1]
A Hall element was manufactured as follows.

  In this reference example, a thin film manufacturing apparatus specially manufactured for manufacturing a compound semiconductor thin film was used. The basic configuration of this device is equipped with a holder for setting the substrate and a heating control device that can heat the substrate to a certain temperature in an ultra-high vacuum chamber, and the vapor pressure of materials such as In, Sb, As, etc. A thin film production apparatus having a plurality of evaporation sources (Knudsen cells) of the material can be controlled. In this apparatus, a single crystal growth of a desired material can be uniformly performed on a substrate according to time-series evaporation control of the vapor pressure of each material and further a substrate heating program by the substrate heating apparatus. In addition to the above functions, if necessary, the donor impurities such as Si and Sn are vapor-pressure controlled in time series so that only a desired portion of the growing thin film has a predetermined concentration. In addition, a thin film manufacturing apparatus equipped with a doping means capable of doping during crystal growth (hereinafter, a molecular beam epitaxy apparatus capable of crystal growth of a single crystal thin film or mixed crystal thin film of a material used in the magnetic sensor part in the present invention: Hereinafter, it may be abbreviated as “MBE apparatus”).

  Using the above-described apparatus, a compound semiconductor thin film constituting the magnetic sensing part of the magnetic sensor of the present invention was manufactured under the following conditions.

A semi-insulating GaAs substrate having a smooth surface was set on the substrate holder of the above apparatus and transferred to a predetermined crystal growth chamber. Next, after the crystal growth chamber was evacuated to ultra high vacuum (2 × 10 ⁻⁸ mbar), InSb and Sn of the dopant were evaporated from the Knudsen cell set in the crystal growth chamber to obtain a thickness of 1. A 0 micron Sn-doped InSb thin film was formed by growing for 60 minutes at a substrate heater indicated temperature of 550 ° C. (substrate temperature of 420 ° C.). At this time, as optimum conditions for obtaining high electron mobility, the vapor beam intensity of In is 1.2 × 10 ⁻⁷ mbr, the vapor beam intensity of Sb is 1.8 × 10 ⁻⁶ mbr, and Sn Knudsen of the dopant Sn is used. The cell temperature was set to 700 ° C., which has little effect on substrate heating. Further, the substrate temperature during growth was kept constant at 420 ° C. In particular, Sn Knudsen cell temperature of 1000 ° C. or lower was suitable as a condition for obtaining high electron mobility. The formed InSb thin film had an electron mobility of 44,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ .

  Further, from the measurement of the activation rate of the dopant, it was found that 50% of the doped Sn emits electrons and exists as cations. This high activity rate suggests that high electron mobility can be obtained and a highly sensitive Hall element can be manufactured.

  Next, a Hall element as shown in FIGS. 2A and 2B was manufactured. In order to form the InSb thin film 2 in a desired pattern, a resist film was formed by a photolithography process, and after dry etching by ion milling, the InSb thin film 2 was etched with a solution containing ferric chloride. A resist pattern for forming a bonding electrode for external connection was formed on this by a photolithography process. Thereafter, Cu and Ni were deposited on the entire surface of the substrate to form a metal layer. The resist pattern and the metal layer deposited thereon were removed by a lift-off process to form a plurality of electrode portions 5 for external connection. A protective layer 3 of silicon nitride was formed on the entire surface of the substrate by plasma CVD, and only the silicon nitride on the bonding electrode portion was removed by reactive ion etching to open a window. A resist is formed by a photolithography process so that the bonding electrode part is opened, and after depositing pure gold on the entire surface, a gold layer is formed only on the bonding electrode part by a lift-off process. A plurality of the Hall elements of the present invention as shown in FIG. 2B were manufactured on a single substrate.

  When the characteristics of the obtained Hall element were measured, the element resistance value at room temperature was 110 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 2.2 mV. Here, the offset voltage means a voltage between the output terminals when 1 V is applied between the input terminals when no magnetic field is applied. The temperature dependency of the resistance of the element was −0.5% / ° C. or less. The ratio between the input resistance values of −50 ° C. and + 150 ° C. was also within double. Furthermore, the Hall voltage obtained with a magnetic field having a magnetic flux density of 0.1 Tesla with an input voltage of 1 V was 210 mV.

  The thin film magnetic sensor of the present invention can be easily manufactured by a wafer process using photolithography as described above, has high productivity, and has a high yield. Further, since the thickness of the thin film magnetic sensing portion is small, the resistance value is 100 ohms or more at room temperature, and the power consumption is small. In addition, there is little variation in the element resistance value due to temperature, and the temperature change of the offset is also small.

  Further, the connection to the external lead can be performed by wire bonding using a standard gold wire with mass productivity. The obtained Hall element is often finished as a sensor by bonding a package after bonding into a resin mold or a thin metal pipe. Furthermore, the output signal of this element is packaged together with a control circuit that digitally amplifies the signal. At this time, it is also preferable to manufacture a control circuit using a Si IC. Since the temperature change of the element resistance value is small, amplification of a small Si substrate circuit chip can also be used for digital amplification.

[Reference Example 2]
A Hall element in which the semiconductor thin film layer was doped with Si was manufactured as follows.

  That is, in this reference example, a thin film manufacturing apparatus specially manufactured for manufacturing a compound semiconductor thin film was used. The basic structure of this device is equipped with a holder for setting the substrate and a heating control device that can heat the substrate to a certain temperature in an ultra-high vacuum chamber, and the vapor pressures of materials such as In, Sb, and Si are individually set. A thin film manufacturing apparatus equipped with an evaporation source (Knudsen cell) of the material that can be controlled in a controlled manner is used. In this apparatus, a single crystal growth of a desired material can be uniformly performed on a substrate according to time-series evaporation control of the vapor pressure of each material and further a substrate heating program by the substrate heating apparatus. In addition to the above functions, if necessary, the donor impurities such as Si and Sn are vapor-pressure controlled in time series so that only a desired portion of the growing thin film has a predetermined concentration. In addition, a thin film manufacturing apparatus equipped with a doping means capable of doping during crystal growth (hereinafter, a molecular beam epitaxy apparatus capable of crystal growth of a single crystal thin film or mixed crystal thin film of a material used in the magnetic sensor part in the present invention: Hereinafter, it may be simply abbreviated as an MBE apparatus).

Using the above-described apparatus, in accordance with the operation of Reference Example 1, on a semi-insulating GaAs substrate having a smooth surface, the substrate heater is in an ultra-high vacuum at an indicated temperature of 550 ° C. (substrate temperature of 420 ° C.). 2 × 10 ⁻⁸ mbar), an InSb thin film was formed by MBE so as to have a thickness of 1.0 μm over 60 minutes. However, a thin film layer was formed by doping Si simultaneously with crystal growth by MBE. At this time, the temperature of the Si Knudsen cell was constant at 1080 ° C. In and Sb were the same as in the reference example. The formed InSb thin film had an electron mobility of 35,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . In order to form the InSb thin film in a desired pattern, a resist film was formed by a photolithography process and etched. Next, wiring portions and bonding electrodes made of a plurality of thin metal thin films were formed on the InSb thin film according to Reference Example 1. Next, in the same manner as in Reference Example 1, a gold layer was formed only on the surface of the bonding electrode, and a large number of Hall elements of the present invention in which the semiconductor thin film was doped with Si were produced on a single substrate.

  When the characteristics of the obtained Hall element were measured, the element resistance value at room temperature was an average of 40 ohms. When a voltage of 1 V is applied to the input electrodes (for example, the electrodes 51 and 53 in FIG. 2A), the value of the offset voltage that appears as a potential difference at the output side electrodes (electrodes 52 and 54 in FIG. 2A) is 0.1. It was ± 1.2 mV, which was found to be extremely small. Further, since the electron mobility of the semiconductor thin film is high, the sensitivity in the magnetic field is large, and the Hall voltage obtained with a magnetic field having a magnetic flux density of 0.1 Tesla with an input voltage of 1 V is 128 mV.

  The temperature change of the input resistance was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. Compared with the temperature change rate of resistance -2.0% / ° C. in the case of a thin film outside the scope of the present invention, the temperature dependence could be greatly reduced.

  Further, this Hall element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor. The obtained magnetic sensor was stably driven as a digital high sensitivity magnetic sensor in a temperature range of −50 ° C. to + 150 ° C.

[Example 3]
A bridge-like magnetoresistive element was manufactured as follows.

In the same manner as in Reference Example 2, the same Si-doped InSb thin film and intermediate layer as in Reference Example 2 were formed on a semi-insulating GaAs substrate having a smooth surface. The formed InSb thin film with a thickness of 1.0 micron had an electron mobility of 35,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, in order to shape the intermediate layer and the InSb thin film into a desired pattern as shown in FIG. 5, a resist film is formed and etched in the same manner as in Reference Example 2, and a part of the intermediate layer is removed by photoetching. A short bar electrode, a wiring part, and a bonding electrode made of a plurality of thin metal thin films were formed on the InSb thin film.

Next, as in Reference Example 2, a gold layer was formed only on the surface of the bonding electrode.
In this way, the four elements that generate the magnetoresistive effect are connected in a bridge shape as shown in FIGS. 5A and 5B, and the two resistive element parts (adjacent to each other) are in a positional relationship with each other. A large number of bridge-shaped magnetoresistive elements of the present invention having a structure in which two non-matching resistor elements are arranged on a plane in a state where they simultaneously receive a magnetic field of the same strength at the same time are manufactured on a single substrate. did. L / W of this magnetoresistive element was 0.25.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was 350 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was 0.1 ± 1.2 mV, which was found to be extremely small. Moreover, it was shown that the single crystal thin film was used and the electron mobility was high, so that the rate of change in resistance of the magnetic field was large and the gear teeth were highly detectable. The temperature change rate of the resistance of the element was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. Compared with the temperature change rate of resistance -2.0% / ° C. in the case of a thin film outside the scope of the present invention, the temperature dependence could be greatly reduced.

  Furthermore, when this element is packaged together with an Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor, the digital high sensitivity is stable between -50 and + 150 ° C. It could be driven as a magnetic sensor.

[Reference Example 4]
A three-terminal magnetoresistive element was manufactured as follows.

On a semi-insulating GaAs substrate having a smooth surface, a semiconductor insulating layer of Ga _0.8 Al _0.2 As _0.2 Sb _0.8 is used in an ultra-high vacuum (2 × 10 ⁻⁸ mbar). 1 was formed to a thickness of 0.3 microns by the MBE method. On top of that, an InSb thin film was formed by MBE to a thickness of 0.3 microns in an ultra-high vacuum (2 × 10 ⁻⁸ mbar).

However, a thin film was formed by doping Si simultaneously with crystal growth by the MBE method. The formed InSb thin film had an electron mobility of 33,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, an Al _0.5 In _0.5 Sb layer was formed as an intermediate layer so as to have a thickness of 0.15 microns. In order to form the intermediate layer and the InSb thin film in a desired pattern, a resist film is formed and etched in the same manner as in Example 3, a part of the intermediate layer is removed by photoetching, and a plurality of thin metal thin films are formed on the InSb thin film. A short bar electrode and a wiring portion were formed. Next, in the same manner as in Example 3, a large number of three-terminal magnetoresistive elements as shown in FIG. 4 were produced on one substrate.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was an average of 100 ohms. When a voltage of 1 V is applied to the input electrodes (for example, the electrodes 51 and 53 in FIG. 4), the value of the offset voltage that appears as a potential difference in the output side electrode (electrode 52 in FIG. 4) is 0.1 ± 1. It was found to be extremely small at 2 mV. In order to investigate the sensitivity in a magnetic field, the magnetoresistance effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 9%.

  In the case of this reference example 4, since the magnetic sensitive part thin film can be made thin, the input resistance of the magnetoresistive element is higher and the power consumption can be reduced as compared with the case of the third example.

  Further, this magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor. The obtained magnetic sensor could be stably driven as a digital high-sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 5]
A three-terminal magnetoresistive element was manufactured as follows.

Similar to Reference Example 4, a semiconductor insulating layer of Ga _0.7 Al _0.3 As _0.1 Sb _0.9 is formed on a semi-insulating GaAs substrate having a smooth surface to a thickness of 0.3 microns. Formed as follows. Next, Al _0.3 In _0.7 Sb was formed to have a thickness of 0.10 microns as a layer for reducing the difference in lattice constant from InSb. On top of that, an InSb thin film doped with Si having a thickness of 0.2 μm was formed in the same manner as in Reference Example 4. The formed InSb thin film had an electron mobility of 41,000 cm ² / Vsec and an electron concentration of 9 × 10 ¹⁶ / cm ³ . Next, an Al _0.5 In _0.5 Sb layer was formed as an intermediate layer so as to have a thickness of 0.15 microns. Next, in the same manner as in Reference Example 4, a large number of three-terminal magnetoresistive elements were manufactured on one substrate. In addition, the electron mobility of the obtained magnetoresistive element was larger than the value of the reference example 4. This is presumably because the magnetoresistive element obtained in Reference Example 5 is provided with a layer that reduces the difference in lattice constant.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was an average of 250 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 1.4 mV. In order to investigate the sensitivity in a magnetic field, the magnetoresistance effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 11%. Moreover, the temperature change of the input resistance was −0.5% / ° C., and the input resistance value at −50 ° C. was within 8 times the resistance value at 150 ° C. Compared with the temperature change rate of resistance -2.0% / ° C. in the case of a thin film outside the scope of the present invention, the temperature dependence could be greatly reduced. Further, in this case, the magnetosensitive portion thin film can be made thin, the input resistance of the magnetoresistive element is high, and the power consumption is low.

  This magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor. The obtained magnetic sensor could be stably driven as a digital high-sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 6]
A Hall element was manufactured as follows.

In the same manner as in Reference Example 5, a semiconductor insulating layer of Ga _0.7 Al _0.3 As _0.1 Sb _0.9 having a thickness of 0.3 μm on a semi-insulating GaAs substrate having a smooth surface, and As a layer for reducing the difference in lattice constant from InSb, Al _0.4 In _0.6 Sb having a thickness of 0.05 μm was formed. On top of that, an InSb thin film having a thickness of 0.1 μm and Al _0.4 In _0.6 Sb having a thickness of 0.15 μm were formed as an intermediate layer in the same manner as in Reference Example 5. However, for the purpose of increasing the electron concentration in the InSb thin film, instead of doping the InSb thin film, a specific part of the intermediate layer, that is, a part in contact with the InSb thin film where the depth from the boundary surface is up to 0.003 microns. Simultaneously with crystal growth, Si was doped. The formed InSb thin film had an electron mobility of 42,000 cm ² / Vsec and an electron concentration of 9 × 10 ¹⁶ / cm ³ . Next, in order to form the intermediate layer and the InSb thin film in a desired pattern as shown in FIGS. 2A and 2B, a resist film is formed and etched in the same manner as in Reference Example 5, and the InSb having the intermediate layer is formed. Wiring parts and bonding electrodes made of a plurality of thin metal thin films were formed on the thin film. Next, in the same manner as in Reference Example 5, a number of Hall elements as shown in FIGS. 2A and 2B were manufactured on a single substrate.

  When the characteristics of the obtained Hall element were measured, the element resistance value at room temperature was an average of 250 ohms as in Reference Example 5. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 1.4 mV. The Hall voltage in a magnetic field with an input voltage of 1 V and a magnetic flux density of 0.1 Tesla was 185 mV. The temperature change rate of the input resistance of the Hall element was −0.5% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. In the case of a thin film outside the range of the present invention, the temperature dependency can be greatly reduced as compared with the temperature change rate of resistance -2.0% / ° C. Further, in this case, the magnetosensitive part thin film can be made thin, the input resistance of the Hall element is high, and the power consumption is low.

  This Hall element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit and a digital output magnetic sensor. The obtained Hall element could be stably driven as a digital high-sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 7]
In Reference Example 4, a three-terminal magnetoresistive element in which the thin film was doped with S was manufactured in the same manner as Reference Example 4 except that the donor atom was changed from Si to S.

  The properties of the thin film obtained at this time were almost the same as in Reference Example 4. Further, when the characteristics of the magnetoresistive element were measured in the same manner as in Reference Example 4, the element resistance value at room temperature was an average of 110 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 0.9 mV. In order to investigate the sensitivity in a magnetic field, the magnetoresistive effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 9%. The temperature change rate of the input resistance of the magnetoresistive element was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C.

  This magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit and a digital output magnetic sensor. The obtained magnetoresistive element could be stably driven as a digital high sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 8]
In Reference Example 4, a three-terminal magnetoresistive element in which the thin film was doped with Sn was manufactured in the same manner as Reference Example 4 except that the donor atom was changed from Si to Sn.

  At this time, the characteristics of the obtained thin film were the same as those in Reference Example 4. Further, when the characteristics of the magnetoresistive element were measured in the same manner as in Reference Example 4, the element resistance value at room temperature was an average of 100 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 0.8 mV.

  In order to investigate the sensitivity in a magnetic field, the magnetoresistive effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 9.0%. The temperature change rate of the input resistance of the magnetoresistive element was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. In the case of a thin film outside the range of the present invention, the temperature dependency can be greatly reduced as compared with the temperature change rate of resistance -2.0% / ° C.

  This magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit and a digital output magnetic sensor. The obtained magnetoresistive element could be stably driven as a digital high sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 9]
A magnetoresistive element was manufactured as follows.

An alumina thin film was formed by 0.25 micron on a single crystal ferrite substrate having a smooth surface by a sputtering method, and the surface of the single crystal ferrite substrate was used as an insulating surface. On the insulating surface of this ferrite substrate, a semiconductor insulating layer of Ga _0.8 Al _0.2 As _0.2 Sb _0.8 is 0.3 by MBE in ultra high vacuum (2 × 10 ⁻⁸ mbar). It was formed to a thickness of micron. Next, an InSb thin film was formed by MBE in an ultrahigh vacuum so as to have a thickness of 0.3 microns. However, a thin film was formed by doping Si simultaneously with crystal growth by the MBE method. The formed InSb thin film had an electron mobility of 33,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, a 0.15 micron Al _0.9 In _0.1 Sb layer is formed as an intermediate layer in the same manner as in Reference Example 4, and a three-terminal magnetoresistive element is formed on a single substrate in the same manner as in Reference Example 4. Many were manufactured.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was an average of 100 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be 0.1 ± 1.2 mV and extremely small. In order to investigate the sensitivity in a magnetic field, the magnetoresistance effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 9%.

  The temperature change of the input resistance was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. The temperature dependency of the thin film outside the range of the present invention can be greatly reduced as compared with the temperature change rate of resistance -2.0% / ° C. Further, in this case, the magnetosensitive part thin film can be made thin, and the input resistance of the magnetoresistive element is higher than that of Reference Example 4 and consumes less power.

  This magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor. The obtained magnetoresistive element could be stably driven as a digital high-sensitivity magnetic sensor in the temperature range of −50 ° C. to + 150 ° C.

[Reference Example 10]
In this reference example, a Hall element as shown in FIGS. 9A and 9B was manufactured. In this figure, in order to simplify the description, the same reference numerals are assigned to the same functions as those in FIGS. 2A and 2B and other figures.

FIG. 9A shows a plan view of the Hall element of this reference example, and FIG. 9B shows a sectional view taken along line IXB-IXB ′ in FIG. 9A. 9A and 9B, the InGaAsSb thin film 2 is formed on an insulating substrate 1. The electron concentration of the thin film 2 is 2.1 × 10 ¹⁶ / cm ³ or more, and the input resistance value of the magnetic sensor at −50 ° C. is within 15 times the input resistance value at 150 ° C. In the figure, reference numeral 4 denotes a wiring portion, which connects the electrode 5 for connection to the outside and the operation layer of the magnetic sensing portion 6. The magnetic sensing unit 6 detects a magnetic field as a magnetic sensor.

  The Hall element having the above structure in which the semiconductor thin film layer was doped with Si was manufactured as follows.

On the semi-insulating GaAs substrate having a smooth surface, an InSb thin film having a thickness of 1.0 micron was formed in an ultrahigh vacuum (2 × 10 ⁻⁸ mbar) using the apparatus described in Reference Example 1 by the MBE method. Formed with. However, a thin film was formed by doping Si simultaneously with crystal growth by MBE. The formed InSb thin film had an electron mobility of 35000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, a Ga _0.9 In _0.1 Sb layer was formed as an intermediate layer to a thickness of 0.15 microns. In order to form the intermediate layer and the InSb thin film in a desired pattern, a resist film was formed by a photolithography process and etched. A wiring part made of a plurality of thin metal thin films and a bonding electrode for connection to the outside were formed on the InSb thin film having the intermediate layer.

  Next, a gold layer was formed only on the surface of the bonding electrode, and a large number of Hall elements of the present invention having an intermediate layer and having a semiconductor thin film doped with Si were produced on a single substrate.

  When the characteristics of the obtained Hall element were measured, the resistance value of the element at room temperature was an average of 40 ohms. When a voltage of 1 V is applied to the input electrodes (for example, the electrodes 51 and 53 in FIG. 9A), the value of the offset voltage that appears as a potential difference on the output side (electrodes 52 and 54 in FIG. 9A) is 0.1 ± 1 It was found to be extremely small at 2 mV. Further, since the electron mobility of the semiconductor thin film is high, the sensitivity in the magnetic field is large, and the Hall voltage obtained with a magnetic field having a magnetic flux density of 0.1 Tesla with an input voltage of 1 V is 130 mV. The temperature change rate of the input resistance is −0.4% / ° C., which is significantly higher than the resistance temperature change rate of −2.0% / ° C. when the InSb thin film of Reference Example 10 not doped with impurities is used. The temperature dependence could be reduced.

[Example 11]
A bridge-like magnetoresistive element was manufactured as follows.

In the same manner as in Reference Example 10, the same Si-doped InSb thin film and intermediate layer as in Reference Example 10 were formed on a semi-insulating GaAs substrate having a smooth surface. The formed 1.0 micron thick InSb thin film had an electron mobility of 35,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, in order to form the intermediate layer and the InSb thin film in a desired pattern as shown in FIG. 5, a resist film is formed and etched in the same manner as in Reference Example 10, and a plurality of thin metals are formed on the InSb thin film having the intermediate layer. A thin film, that is, a short bar electrode composed of two layers of Cu / Ni, a wiring part, and a bonding electrode composed of three layers of Cu / Ni / Au were formed.

  Next, as in Reference Example 10, a gold layer was formed only on the surface of the bonding electrode. In this way, the four elements that generate the magnetoresistive effect are connected in a bridge shape as shown in FIGS. 5A and 5B, and the two resistive element parts (adjacent to each other) are in a positional relationship with each other. A large number of differential magnetoresistive elements of the present invention having a structure in which two non-matching resistive element portions) are arranged on a plane in a state where they simultaneously receive a magnetic field of the same strength at the same time are manufactured on a single substrate. did. However, the ratio L / W value between the length L and the width W between the short bar electrodes of the magnetoresistive element was 0.25.

  When the characteristics of the obtained magnetoresistive element were measured, the resistance value of the element at room temperature was 350 ohms. The resistance change rate in a magnetic field with a magnetic flux density of 0.1 Tesla was 9%, and it was found that the resistance change rate in the magnetic field was large and the sensitivity was good. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be 0.1 ± 1.2 mV and extremely small. It was also shown that a single crystal thin film was used and the electron mobility was high, so that the rate of change in the resistance of the magnetic field was large and the ability to detect gear teeth was high. Further, the temperature change rate of the resistance of the element is −0.4% / ° C., and the temperature dependency of the resistance in the case of the InSb thin film not doped with impurities is significantly higher than the temperature change rate of −2.0% / ° C. It was possible to reduce. It was found that a digital output magnetic sensor formed by connecting a Si IC differential digital amplifier to this element and formed in one package has an excellent gear tooth detection ability.

[Reference Example 12]
A three-terminal magnetoresistive element was manufactured as follows.

In the same manner as in Reference Example 10, an InSb thin film having a thickness of 1.0 micron with an electron mobility of 50,000 cm ² / Vsec, an electron concentration of 4 × 10 ¹⁶ / cm ³ doped with a small amount of Sn on a GaAs substrate An intermediate layer of 0.2 micron thick Al _0.2 In _0.8 Sb was formed. Next, in order to form the intermediate layer and the InSb thin film in a desired pattern, a resist film was formed by a photolithography process and etched in the same manner as in Reference Example 10. A resist pattern for forming a short bar electrode, a wiring portion, and a bonding electrode made of a plurality of thin metal thin films was formed thereon by a photolithography process. Thereafter, in the same manner as in Reference Example 10, a short bar electrode, a plurality of electrodes for external connection, and a wiring portion were formed. Next, a gold layer was formed only on the surface of the bonding electrode in the same manner as in Reference Example 10. In this way, a large number of three-terminal magnetoresistive elements having three bonding electrodes as shown in FIG. 4 were produced on one substrate. However, the ratio L / W value between the length L and the width W between the short bar electrodes of the magnetoresistive element was 0.25.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was 810 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be extremely small at 0.1 ± 2.1 mV. In addition, since a single crystal thin film is used and the electron mobility is high, the rate of change in resistance of the magnetic field is large, and a resistance change of 14% is obtained in a magnetic field with a magnetic flux density of 0.1 Tesla, which is high resistance, and the gear teeth It was shown that the detectability of is extremely high.

  It was found that this device can be easily manufactured by a wafer process applying photolithography, has mass productivity, and has a high yield. Further, since the film thickness of the thin film magnetic sensing portion, that is, the magnetoresistive element portion is small, the resistance value is 300 ohms or more at room temperature, and the power consumption is small.

  Furthermore, the connection to the external lead can be performed by wire bonding using a standard gold wire with mass productivity. The obtained magnetoresistive element is often finished as a sensor by embedding a package after bonding in a resin mold or a thin metal pipe. Further, it is packaged together with a control circuit for amplifying and digitally amplifying the differential output signal of this element. At this time, it is also preferable to manufacture a control circuit using a Si IC. This is a magnetic sensor that has a high detection capability of the rotating gear and detects the rotational speed and the like.

[Reference Example 13]
A three-terminal magnetoresistive element was manufactured as follows.

On a semi-insulating GaAs substrate having a smooth surface, a semiconductor insulating layer of Ga _0.7 Al _0.3 As _0.1 Sb _0.9 is applied in an ultrahigh vacuum (2 × 10 ⁻⁸ mbar) by the MBE method. To 0.3 microns. On top of that, an InSb thin film having a thickness of 0.3 microns was formed by the MBE method. However, a thin film was formed by doping Si simultaneously with crystal growth by MBE. The formed InSb thin film had an electron mobility of 33,000 cm ² / Vsec and an electron concentration of 7 × 10 ¹⁶ / cm ³ . Next, an Al _0.9 In _0.1 Sb layer was formed as an intermediate layer so as to have a thickness of 0.15 microns. In order to form the intermediate layer and the InSb thin film in a desired pattern, a resist film was formed by a photolithography process and etched. A short bar electrode made of a plurality of thin metal thin films, a wiring portion, and a bonding electrode for connection to the outside were formed on the electrode. Next, in the same manner as in Example 11, a gold layer was formed only on the surface of the bonding electrode, and a large number of three-terminal magnetoresistive elements were manufactured on one substrate. However, the ratio L / W between the length L and the width W between the short bar electrodes of the magnetoresistive element was 0.20.

  When the characteristics of the obtained magnetoresistive element were measured, the resistance value of the element at room temperature was an average of 320 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be 0.1 ± 1.2 mV and extremely small. The resistance change in a magnetic field with an input voltage of 1 V and a magnetic flux density of 0.1 Tesla was 10%. Further, the temperature change rate of the input resistance is −0.4% / ° C., and the temperature change rate of the resistance in the case of the InSb thin film not doped with impurities is significantly higher than the temperature change rate of −2.0% / ° C. It was possible to reduce. Further, in this case, the magnetosensitive part thin film can be made thin, the input resistance of the magnetoresistive element is high, and the power consumption is low.

[Reference Example 14]
A three-terminal magnetoresistive element was manufactured as follows.

In the same manner as in Reference Example 13, a Ga _0.7 Al _0.3 As _0.1 Sb _0.9 semiconductor insulating layer was formed on a GaAs substrate so as to have a thickness of 0.3 microns. Next, Al _0.9 In _0.1 Sb was formed to have a thickness of 0.10 microns as a buffer layer to reduce the difference in lattice constant from InSb. An InSb thin film doped with Si having a thickness of 0.1 μm and an Al _0.9 In _0.1 Sb film with a thickness of 0.15 μm were formed in the same manner as in Reference Example 13 thereon. The formed InSb thin film had an electron mobility of 41,000 cm ² / Vsec and an electron concentration of 9 × 10 ¹⁶ / cm ³ . Next, in order to form an InSb thin film or the like in a desired pattern, a resist film was formed by a photolithography process and etched. Thereafter, in the same manner as in Reference Example 13, a short bar electrode made of a plurality of thin metal thin films, a wiring portion, and a bonding electrode for connection to the outside were formed. Next, in the same manner as in Reference Example 13, a gold layer was formed only on the surface of the bonding electrode, and a large number of three-terminal magnetoresistive elements were manufactured on one substrate.

  When the characteristics of the obtained element were measured, it was found that the value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was 0.1 ± 1.4 mV, which was extremely small. The rate of change in resistance in a magnetic field with an input voltage of 1 V and a magnetic flux density of 0.1 Tesla was 14%. Also, the temperature change rate of the input resistance is -0.5% / ° C, and the temperature dependency is greatly reduced compared to the temperature change rate of the resistance in the case of a thin film outside the present invention -2.0% / ° C. We were able to. Further, in this case, the magnetosensitive portion thin film can be made thin, the input resistance of the magnetoresistive element is high, and the power consumption is low.

[Comparative Example 1]
In Reference Example 14, a comparative three-terminal magnetoresistive element having no intermediate layer was manufactured in the same manner as Reference Example 14 except that the intermediate layer was not formed. The characteristics of the obtained magnetoresistive element were measured in the same manner as in Reference Example 14. As a result, the sensitivity decreased with a decrease in electron mobility of about 35%, and the resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla. Was less than 9%

[Reference Example 15]
A three-terminal magnetoresistive element was manufactured as follows.

In the same manner as in Reference Example 14, the difference in lattice constant between the semiconductor insulating layer of Ga _0.7 Al _0.3 As _0.1 Sb _0.9 with a thickness of 0.3 μm and InSb is reduced on the GaAs substrate. As a layer to be formed, a buffer layer of 0.10 micron Al _0.9 In _0.1 Sb was formed. However, Si was doped simultaneously with crystal growth in a specific part of the intermediate layer, that is, a part in contact with the InSb thin film and having a depth of 0.003 microns from the interface. The formed thin film had an electron mobility of 38,000 cm ² / Vsec and an electron concentration of 9 × 10 ¹⁶ / cm ³ . Next, in order to form the intermediate layer and the InSb thin film in a desired pattern, a resist film is formed and etched in the same manner as in Reference Example 14, and a plurality of thin metal thin films are formed on the intermediate layer on the InSb thin film. A short bar electrode, a wiring portion, and a bonding electrode for connection to the outside were formed. Next, a silicon nitride protective layer was formed in the same manner as in Reference Example 14, and after opening only the bonding electrode portion, a gold layer was formed only on the surface of the bonding electrode. In this manner, a large number of three-terminal magnetoresistive elements were manufactured on one substrate.

  When the characteristics of the obtained magnetoresistive element were measured, it was found that the value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was 0.1 ± 1.4 mV, which was extremely small. The resistance change in a magnetic field with an input voltage of 1 V and a magnetic flux density of 0.1 Tesla was 12%. The temperature change rate of the input resistance of the magnetoresistive element is −0.5% / ° C., which is much more temperature dependent than the temperature change rate of resistance in the case of an InSb thin film not doped with impurities—2.0% / ° C. Can be reduced. Further, in this case, the magnetosensitive portion thin film can be made thin, the input resistance of the magnetoresistive element is high, and the power consumption is low.

[Reference Example 16]
In Reference Example 13, a three-terminal magnetoresistive element in which the thin film was doped with S was manufactured in the same manner as Reference Example 13 except that the donor atom was changed from Si to S.

  The properties of the thin film obtained at this time were almost the same as those of Reference Example 13. Further, when the characteristics of the magnetoresistive element were measured in the same manner as in Reference Example 13, the average resistance value of the element at room temperature was 300 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be 0.1 ± 0.2 mV, which was extremely small. The change in resistance with a magnetic field was 9%. The temperature change rate of the input resistance of the magnetoresistive element was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. In the case of an InSb thin film not doped with an impurity, the temperature change rate of the resistance can be reduced to 1/5 compared to the temperature change rate of −2.0% / ° C., and the temperature dependence can be greatly reduced. .

  This magnetoresistive element was packaged together with an Si IC control circuit to produce a magnetic sensor with an amplifier circuit and a digital output magnetic sensor. The obtained resistance element could be stably driven as a digital high sensitivity magnetic sensor in a temperature range of −50 ° C. to 150 ° C.

    [Reference Example 17]

  In this reference example, a two-terminal magnetoresistive element as shown in FIGS. 10A and 10B was manufactured. In this figure, in order to simplify the description, the same reference numerals are given to the components having the same functions as the structures shown in the respective drawings.

  FIG. 10B shows a plan view of the two-terminal magnetoresistive element of this reference example having two external connection electrodes, and FIG. 10A shows the magnetoresistive element of FIG. 10B cut along the XA-XA ′ line. Sectional drawing when doing is shown. On the substrate 1, an InAsSb thin film 2, a magnetoresistive effect element portion 21, and an electrode 5 for external connection are formed. Reference numeral 6 denotes a magnetic sensing part for detecting a magnetic field as a magnetic sensor. Reference numeral 10 denotes a high-conductivity portion formed in ohmic contact with the InGaAsSb of the magnetosensitive portion in order to increase the magnetoresistance effect of the InGaAsSb thin film, and is a short bar electrode. The short bar electrode is usually made of a metal thin film that can make ohmic contact with the operating layer, and may be a multilayer or a single layer. The InAsSb thin film 2 may be doped with a donor atom 12 such as Si. Further, the uppermost surfaces of the electrode and the wiring part formed on the operation layer may not be gold.

  A magnetoresistive element having such a configuration was manufactured as follows.

In the same manner as in Reference Example 10, a small amount of Sn was doped on a GaAs substrate, and an InSb thin film having an electron mobility of 51,000 cm ² / Vsec, an electron concentration of 4 × 10 ¹⁶ / cm ³ , and a thickness of 1.0 micron. And an interlayer of Al _0.2 In _0.8 Sb with a thickness of 0.2 microns was formed. Next, in order to form the intermediate layer and the InSb thin film in a desired pattern as shown in FIGS. 10A and 10B, a resist film was formed by a photolithography process and etched in the same manner as in Reference Example 10. A resist pattern for forming a short bar electrode, a wiring portion, and a bonding electrode made of a plurality of thin metal thin films was formed thereon by a photolithography process. Thereafter, in the same manner as in Reference Example 10, a short bar electrode, a plurality of electrodes for external connection, and a wiring portion were formed. Next, a gold layer was formed only on the surface of the bonding electrode in the same manner as in Reference Example 10. In this way, a number of two-terminal magnetoresistive elements as shown in FIGS. 10A and 10B were produced on one substrate. However, the ratio L / W between the length L and the width W between the short bar electrodes of the magnetoresistive element was 0.20.

  When the characteristics of the obtained magnetoresistive element were measured, the element resistance value at room temperature was 500 ohms. Moreover, since a single crystal thin film was used and the electron mobility was high, the resistance change rate of the magnetic field was large, and a resistance change rate of 15% was obtained under a magnetic flux density of 0.1 Tesla. Therefore, it was found that the detection ability of the gear teeth is extremely large.

  It was found that this device can be easily manufactured by a wafer process applying photolithography, has mass productivity, and has a high yield.

  Furthermore, the connection to the external lead can be performed by wire bonding using a standard gold wire with mass productivity. The obtained magnetoresistive element is often finished as a sensor by embedding a package after bonding in a resin mold or a thin metal pipe. Further, it is also packaged together with a control circuit for amplifying a differential output signal obtained by a circuit constituted by connecting this element and a fixed resistance element formed on a Si IC. In that case, it is also preferable to manufacture the control circuit on the same IC chip as the fixed resistance element.

[Reference Example 18]
A three-terminal magnetoresistive element was produced as follows.

An alumina thin film was formed on a Ni—Zn single crystal ferrite substrate having a smooth surface by 0.25 micron by sputtering, and the ferrite substrate surface was made an insulating surface.
On the insulating surface of the ferrite substrate, a semiconductor insulating layer of Ga _0.8 Al _0.2 As _0.2 Sb _0.8 is obtained in an ultrahigh vacuum (2 × 10 ⁻⁸ mbar) by an MBE method. It was formed to a thickness of 3 microns. Next, an InSb thin film was formed thereon by MBE so as to have a thickness of 0.3 microns in an ultra vacuum. However, a thin film was formed by doping Sn simultaneously with the crystal growth by the MBE method. The formed InSb thin film had an electron mobility of 33,000 cm ² / Vsec and an electron concentration of 8 × 10 ¹⁶ / cm ³ . Next, 0.15 micron Al _0.9 In _0.1 Sb was formed as an intermediate layer. Thereafter, in the same manner as in Reference Examples 14 and 5, a large number of three-terminal magnetoresistive elements having a silicon nitride layer as a protective layer on the surface were produced on one substrate.

  When the characteristics of the obtained magnetoresistive element were measured, the resistance value of the element at room temperature was an average of 320 ohms. The value of the offset voltage on the output side when a voltage of 1 V was applied to the input electrode was found to be 0.1 ± 1.2 mV and extremely small. In order to investigate the sensitivity in a magnetic field, the magnetoresistance effect was investigated. The resistance change in a magnetic field with a magnetic flux density of 0.1 Tesla was 9%. The change in temperature of the input resistance was −0.4% / ° C., and the input resistance value at −50 ° C. was within 5 times the resistance value at 150 ° C. Compared with the temperature change rate of resistance of −2.0% / ° C. in the case of an InSb thin film not doped with impurities, the temperature dependence could be greatly reduced. Further, in this case, the magnetosensitive part thin film can be made thin, the input resistance of the magnetoresistive element is high, and the power consumption is low.

  This magnetoresistive element was packaged together with a Si IC control circuit to produce a magnetic sensor with an amplifier circuit, that is, a digital output magnetic sensor. The obtained magnetoresistive element could be stably driven as a digital high sensitivity magnetic sensor within a temperature range of −50 ° C. to + 150 ° C.

[Comparative Example 2]
In Reference Example 18, a comparative three-terminal magnetoresistive element having no intermediate layer was manufactured in the same manner as Reference Example 18 except that the intermediate layer was not formed. When the characteristics of the obtained magnetoresistive element were measured in the same manner as in Reference Example 18, the magnetoresistive element had a sensitivity reduction of about 30% due to a decrease in electron mobility, and the resistance change due to the magnetoresistive effect was 6%. Met.

  As described above, in the present invention, by providing the intermediate layer, the decrease in electron mobility due to the formation of the protective film can be extremely reduced, and a highly sensitive magnetic sensor can be manufactured.

  The magnetic sensor of the present invention is less susceptible to fluctuations in element resistance and offset drift due to temperature, can measure a very small magnetic field with high sensitivity, and has less noise inherent to the element. As a result, a magnetic sensor capable of driving a wide temperature range from low to high as well as around room temperature with a simple drive circuit has been realized. The magnetic sensor of the present invention can detect rotation of a gear or the like with high sensitivity.

  Moreover, since the thin film is used for the magnetic sensitive part and the magnetic sensitive part thin film is manufactured using a photolithography process, the pattern accuracy is good and the offset voltage is small. Furthermore, the temperature change of the input resistance value of the magnetic sensor can be reduced by the composition setting or doping of the magnetic sensitive part thin film, and the load current of the drive circuit including amplification control for amplifying the magnetic sensor output or supplying power to the magnetic sensor The drive circuit can be downsized. Furthermore, since the amplification control circuit can be miniaturized, a package integrated with a magnetic sensor chip is possible, and it can be used as a magnetic sensor (so-called magnetic sensor IC) that is small and can obtain a digital output or a linear output.

  In particular, an element in which a drive amplifier circuit element of Si LSI and the magnetic sensor of the present invention are integrated and packaged is within the scope of the present invention, and a small magnetic sensor that detects a magnetism and outputs a digital signal can be manufactured. It is highly versatile and has a wide range of applications as a small contactless sensor. It is also a magnetic sensor that can be used for high-speed rotation detection.

It is a graph which shows the temperature dependence of the resistance value of an InSb thin film. It is a top view of the Hall element of the present invention. It is sectional drawing of a Hall element. It is sectional drawing which shows typically the state by which the Hall element of this invention was connected with the lead | read | reed and it was resin-packaged. It is the figure which showed typically the one aspect | mode of the 3 terminal magnetoresistive element of this invention. It is a top view which shows the one aspect | mode of the magnetoresistive element of this invention. It is sectional drawing of the magnetoresistive element shown to FIG. 5A. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is sectional drawing which showed the laminated structure of the thin film in the magnetic sensing part of the magnetic sensor of this invention. It is a circuit diagram of a magnetic sensor in a state packaged with a silicon integrated circuit chip. It is a top view of the Hall element formed in Reference Example 10 of the present invention. It is sectional drawing of the Hall element shown in FIG. 9A. It is sectional drawing of the 2 terminal magnetoresistive element formed in the reference example 18 of this invention. FIG. 10B is a plan view of the magnetoresistive element shown in FIG. 10A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 InGaAsSb thin film 3 Protective film 4 Wiring part 5 (51, 52, 53, 54) Electrode 6 (61, 62, 63, 64) Magnetoresistance element part 10 Short bar electrode 21 Magnetoresistance effect element part

Claims (5)

  On a smooth substrate surface, there are four magnetoresistive element portions, wiring portions, and bonding electrodes made of a semiconductor thin film, and the four magnetoresistive element portions are connected in a bridge structure, Of the four element parts, two element parts in the positional relationship of the edges of the bridge structure are arranged in a state where they simultaneously receive a magnetic field of the same strength vertically, and the element part and the bonding electrode are A semiconductor magnetoresistive device connected by a wiring portion.   The semiconductor magnetoresistive device according to claim 1, wherein the wiring portions do not intersect.   3. The semiconductor magnetoresistive device according to claim 1, wherein resistance values of wiring portions from a connection point connecting the four element portions to the bonding electrode are equal to each other. . The semiconductor thin film is a _single- layer In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) thin film layer formed directly on a substrate, and the thin film layer includes 4. The semiconductor magnetoresistive device according to claim 1, comprising at least one donor atom selected from the group consisting of Si, Te, S, Sn, Ge, and Se. The semiconductor thin film is a _single- layer In _x Ga _1-x As _y Sb _1-y (0 <x ≦ 1, 0 ≦ y ≦ 1) thin film layer formed directly on a substrate, The electron concentration is 2.1 × 10 ¹⁶ / cm ³ or more, and the relationship between the electron mobility μ (cm ² / V · s) and the electron concentration n (1 / cm ³ ) of the thin film layer is
Log ₁₀ (n) + 4.5 × 10 ⁻⁵ × μ ≧ 18.0
The semiconductor magnetoresistive device according to claim 1, wherein:

Images